Recently data centers are seeking to integrate virtual machines (VMs) on physical servers through virtualization to improve the use efficiency of resources (computing resources) and to obtain scale economic effects through scale enlargement.
On the other hand, accompanying the virtualization and increased scale of the system, operation management of the system is becoming complicated. For example, the virtualization needs additional operation management operations such as VM image management and migration control. Increases in scale are accompanied by increases in the frequency at which the operation management operations have to be performed. Related prior arts are described in Japanese Laid-Open Patent Publication Nos. 2002-024192 and 2005-293048 Patent Documents, for example.
Nonetheless, with conventional technologies, a problem arises in that resource load may increase consequent to the simultaneous occurrence of multiple operation management operations.